1. Field of the Invention
The present invention relates to decarbonization of the coking chamber of a coke oven, more particularly an apparatus for removing the carbon deposition on the inside of the coking chambers.
2. Description of Prior Arts
In coke production in coke ovens, carbon deposits on all parts of the coking chamber during the coking period and if this carbon deposition, particularly on the inside walls of the coking chamber, is allowed to accumulate, it hinders the pushing-out operation of the produced coke through the chamber, decreases the effective dimensions of the chamber, and causes lowering in the thermal conductivity of the chamber walls and the adverse effects on the coke production. Therefore, the carbon deposition on the inside walls of the coking chamber must be removed periodically. Meanwhile, if the carbon deposition on the upper inside wall (ceiling surface) of the coking chamber is allowed to accumulate, it hinders the levelling operation of the coal charges, and this carbon deposition also must be removed periodically. Also the carbon deposition on the root portion and the rising portion of the ascension pipe, if allowed to accumulate, hinders the outlet of the generated gases, and must be removed periodically. In the conventional arts, as taught by Japanese Patent Publication No. Sho 60-2348, it has long been a common practice for the removal of the carbon deposition on the inside walls of the coking chamber that a spear-like tool of about 5 to 6 meters in length, with a pointed tip, is used for manually stripping off the carbon deposits from above the coking chamber. This practice, however, has been confronted with various problems such that the carbon deposition layer is completely stripped off from the walls without leaving the least carbon deposition necessary for sealing the wall refractory joints, the workers are exposed to a high temperature and heavy muscular labor and that the oven operation must be stopped during the stripping off of the carbon deposits. Further, for the removal of the carbon deposits on the ceiling surface or on the upper portions of the side walls of the coking chamber, which are at the dead angle from above the coking chamber, it is difficult to strip them off by the conventional practice.
In substitution of the above conventional practice, it has been proposed to liberate the coal charging holes and the ascension pipe about one hour before the pushing-out of the coke to introduce air into the chamber by a natural ventilation for combustion of the carbon deposits. However, the introduction of air about one hour before the pushing-out of the coke from the chamber has economical and technical problems that much of the oven gas is wastefully discharged together with the introduced air through the ascension pipe, because the oven gas is still generated at a rate of about 3 to 5 Nm.sup.3 /Hr.Coal t. (4800 Kcal/Nm.sup.3) at this stage, and that the coal charging holes and portions nearby are unduely cooled by the introduced air and very susceptible to damages such as by spalling.
For removal of the carbon deposits on the root portion and rising portion of the ascension pipe, the conventional practice is that in addition to the above-mentioned introduction of air through the coal charging holes, the levelling bar hole is liberated before the pushing-out of the coke to introduce air therethrough for combustion of the carbon deposit and the carbon deposit is mechanically sticked off by a tool from through the levelling bar hole or through the top hole of the rising portion of the ascension pipe. All of these practices have been confronted with the problem that the oven gas generating during these decarbonization operations is discharged from the coking chamber.